1. Field of the Invention
The present invention relates to a photo sensor, a display panel having the same and a display device having a display panel.
2. Description of the Related Art
Generally, a liquid crystal display device is classified as either a transmissive type liquid crystal display device, which displays images using an internal light source such as a backlight assembly, or a transmissive and reflective type liquid crystal display device which displays images using an internal light source or by reflecting an external incident light.
The transmissive and reflective type display device controls power supplied to a backlight assembly in response to an intensity of the external incident light. Specifically, when the external incident light has a lower intensity, the transmissive and reflective type display device operates in a transmission mode such that the backlight assembly is turned on and internal light transmitted by the backlight assembly is used to display images. When the external incident light has a higher intensity, the transmissive and reflective type display device operates in a reflective mode such that the backlight assembly is turned off and the external incident light is reflected to display images. Additionally, a gamma level is automatically adjusted corresponding to either the transmission mode or the reflective mode so that an image displaying quality is improved.
Thus, power consumption of the transmissive and reflective type display device is reduced by controlling the power supplied to the backlight assembly in response to the intensity of the external incident light. Additionally, when the gamma level is adjusted according to a respective operational mode of the liquid crystal display device, the image displaying quality is improved. Accordingly, a photo sensor disposed on a display panel of the liquid crystal display device to sense the intensity of the external incident light is required to reduce the power consumption of the liquid crystal display device.